3-Aryloxypyrazole-1-carboxamides useful as herbicide active ingredients are produced by O-arylation of the hydroxy group at the 3-position of 3-hydroxypyrazole and subsequent N-carbamoylation on the nitrogen atom at the 1-position of the pyrazole ring (International Patent Publication No. 02/066439). In the above production route, however, the regioselectivity for the O-arylation is poor and a byproduct is formed in which arylation has taken place on the nitrogen atom at the 1-position of the pyrazole ring, so that it cannot necessarily be said that the above process is industrially desirable.
Of compounds of the following general formula (I),
there is described ethyl 3-hydroxypyrazole-1-carboxylates which is the compounds of the general formula (I) in which R2 and R4 are hydrogen atoms and R1 is a methyl group, in which R2 and R4 are hydrogen atoms and R1 is a propyl group or in which R2 is an ethyl group, R4 is a hydrogen atom and R1 is a methyl group. However, no process for the production thereof is described in detail (see U.S. Pat. No. 4,320,132).